This invention relates to a method and apparatus for the production of doped crystals, and more particularly a method and apparatus for growing doped silicon crystals, especially antimony-doped silicon crystals.
The invention is especially directed to the growing of doped silicon single crystals by the Czochralski process (the "CZ" process), and more particularly to the growing of such crystals with antimony as the dopant.
Reference may be made to U.S. Pat. No. 4,134,785 issued Jan. 16, 1979, U.S. Pat. No. 4,556,448 issued Dec. 3, 1985, and U.S. Pat. No. 5,423,283 issued Jun. 13, 1995 for information re doping generally, and particularly to the last of these three patents for information re doping with antimony involving a method for growing an antimony-doped silicon single-crystal utilizing the CZ process wherein inert gas (argon) is introduced into the crucible chamber and maintained at a pressure in the range of 10-50 millibars, polycrystalline silicon is melted in the crucible in the chamber, and antimony pellets put into the molten silicon (see column 3, lines 41-42 of U.S. Pat. No. 5,423,283. How the antimony pellets are added is not specified.